21252653 has 2 divisors, whose sum is σ = 21252654. Its totient is φ = 21252652.

The previous prime is 21252617. The next prime is 21252677. The reversal of 21252653 is 35625212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15856324 + 5396329 = 3982^2 + 2323^2 .

It is a cyclic number.

It is not a de Polignac number, because 21252653 - 2⁶ = 21252589 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21252353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10626326 + 10626327.

It is an arithmetic number, because the mean of its divisors is an integer number (10626327).

Almost surely, 2^21252653 is an apocalyptic number.

It is an amenable number.

21252653 is a deficient number, since it is larger than the sum of its proper divisors (1).

21252653 is an equidigital number, since it uses as much as digits as its factorization.

21252653 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3600, while the sum is 26.

The square root of 21252653 is about 4610.0599779179. The cubic root of 21252653 is about 276.9944391921.

Adding to 21252653 its reverse (35625212), we get a palindrome (56877865).

The spelling of 21252653 in words is "twenty-one million, two hundred fifty-two thousand, six hundred fifty-three".